In a bicycle having a motor-driven derailleur, a motor for changing gears is located at a position where the derailleur is mounted. A motor control unit and a power battery are mounted on the bicycle at appropriate positions. An operating mode switching unit is attached to a handlebar and provides a control signal to the motor control unit. When an automatic mode is selected by the operating mode switching unit, the control unit automatically selects a transmission gear ratio corresponding to the speed of the bicycle sensed by a speed sensor mounted on the bicycle, and then causes the motor to shift gears to the one corresponding to the selected transmission gear ratio. When a manual mode is selected by the switching unit, the transmission gear ratio can be changed stepwise by manually operating a button provided in the switching unit. The switching between the automatic mode and the manual mode is provided by operating an operating mode switch included in the switching unit.
As the operating mode switch, a rotary switch may be used.
The operating mode switching unit is usually mounted on the handlebar of the bicycle. Therefore, the switching unit should be compact and also easy to operate. But, a rotary switch is relatively large, which is a bottleneck in downsizing the switching unit.
An object of the present invention is to provide an operating mode switching unit having a compact operating mode switch.